A web server uses relatively small text data called “HTTP Cookie (hereinafter, referred to as “Cookie information”)” for identification of a client which accesses the web server. When a user accesses a website on the web server, the Cookie information is transmitted to a user's web browser, and stored in a hard disk or a memory. In a case where the user inputs a setting or the like while browsing the web site, Cookie information indicating content of such an input is stored. After that, when the user accesses the website via the same web browser again, the Cookie information is automatically transmitted from the web browser to the web server.
This allows the web server to identify the client (web browser) which accesses the web server. The use of the Cookie information makes it possible to provide useful functions such as a function of allowing a user to execute an automatic login process from a user's second access to a destination. In recent years, the Cookie information has been therefore considered as an important function that provides a user with a smooth web access.
Patent Literature 1 discloses a single sign-on system employing the Cookie information, in which (i) a first web server identifies a specific HTTP client and issues Cookie information for the client, and (ii) the user can access, with the use of the Cookie information, not only the first web server but also the second web server.
Further, in recent years, there has been known such a technique that a multifunction apparatus displays an operation screen by use of a web browser on the basis of an HTML document obtained from an external PC. Patent Literature 2 discloses a multifunction apparatus control system including: a multifunction apparatus; and a control apparatus for transmitting a control instruction to the multifunction apparatus via a communication network, for example. In the multifunction apparatus control system, the control device transmits data of the operation screen to the multifunction apparatus by use of the HTTP, and the multifunction apparatus uses a web browser to display the operation screen. Then, the control device transmits a control command to the multifunction apparatus by use of an SOAP in response to an instruction inputted on the operation screen, and the multifunction apparatus executes a function corresponding to the control command.